Fluid pressure operated gun



Sept- 22, 1953 E. R. FITCH FLUID PRESSURE OPERATED GUN Original FiledDec. 28, 1944 aWMMUVAIIVi-J.

INVENTR.

Elle@ i?. Fife/L. BY

A 7`TRNEYS Patented Sept. 22,` 1953 FLUID PRESSURE OPERATED GUN ElleryR. Fitch, Elyria, Ohio, assigner to Bendix- Westinghouse Automotive AirBrake Company, Elyria, Ohio, a corporation of Delaware Originalapplication December 28, 1944, Serial No. 570,189, now Patent No.2,566,181, dated August 28,1951. Divided and this application November20, 1950, Serial No. 196,596

Claims. (Cl. 124-13) 'This invention relates to guns, and moreparticularly to guns of the type wherein compressed air and othercompressed gases are utilized as the propelling force for the projectileof the gun.

It has previously been proposed to utilize compressed air inV guns forthe above purpose, but many of these guns have required an unnecessaryamount of manual effort for compressing the gas, and it is accordinglyan object of the present invention to provide means for supplyingcompressed gas for the operation of the gun so designed as to limit orentirely eliminate this manual effort on the part of the operator.

It has also been proposed to provide a storage reservoir for compressedgas on guns, but in many cases these reservoirs have either beenunnecessarily large or of insufficient capacity, and it is a furtherobject of the invention to provide means for storing compressed gas in agun of the above type, so constituted as to provide a supply ofcompressed gas sufiicient to operate the gun over a long period of time,and at the same time to appreciably reduce the size of the comn Ypressed gas reservoir required for this purpose.

Yet anotherl object of the invention is to provide, in connection with agun ofthe above type having a storage reservoir charged with gas underpres-sure, manually operated means controlled by the operator forincreasing the pressure of the gas supplied from the reservoir to thefiring chamber.

'Still another object of the invention is to provide, in a gun of theabove type, means for permitting manual compression of air in theprojectile chamber in the event of depletion of the compressed gas inthe supply reservoir.

A further object of the invention is to provide novel and eicientmeansrfor controlling the flow of gas from the reservoir to the Vfiringchamber.

Another object of the invention is to provide simple and efficient meansfor preventing or minimizing leakage of compressed gas from the fluidpressure system of the gun.

AA still further object of the invention is to provide simple andeiiicient means for feeding vprojectiles from a magazinev to the barrelof the gun.

Yet another object of the invention is to provide a gun of the abovetype, so constructed as.

to insure improved accuracy in the firing of the gun by the operator.

These and other novel features and objects of the invention will appearmore fully hereinafter from the following detailed description whentaken in connection with the v accompanying drawing,- ,wheren one formof the present invention is illustratedA It is to be expresslyunderstood, however, that the drawing is utilized for purposes ofillustration only, and is not designed as a definition of the limits ofthe invention, reference being had for this purpose to the appendedclaims.

In the drawing, wherein similar reference characters refer to similarparts throughout the several views:

Fig. 1 is a sectional side view of a gun constructed in accordance withthe principles of the present invention, and

Fig. 2 is a view of the gun taken from the right end of Fig. 1.

Referring more particularly to Fig. l, the gun is provided with a bodyportion 4 which may be made of metal or other suitable substance, thebody being provided with a handle 5 and a barrel 6 extendinglongitudinally of the body and arranged in relation to the body andhandle as shown. The left portion of the body is provided with areservoir I closed at its lower end by means of a threaded plug 8 andconnected at its upper end by means of a conduit .9 to the left end of acylinder II)r formed in the body. A piston I I, having a packing cup I2of rubber or other suitable material, is slidably mounted inthe cylinderI0, the piston being provided with an operating rod I3 attached theretoand adapted to slide through a bore I4 in the body, and a sealingelement I5 being mounted in the bore which acts to prevent leakage toatmosphere from the left end of the cylinder. The left end of the stem I3 is provided with a head portion I6, and the piston and stem arenormally maintained in the position shown by a spring Il interposedbetween the right surface of the head I 6 and the body.

The handle portion of the body is provided with a bore I8 aligned withthe barrel 6 and of substantially the same diameter, this bore beingnormally closed by means of a plunger I9 provided at its right end witha T-shaped head 20 having i an arm 2l adapted in the position shown toengage a notch 22 formed in the handle in order to prevent movement ofthe plunger to the right. A projectile magazine or bore 23 is formed inthe handle as shown, the lower end of the bore being provided with athreaded plug 24, and the upper end of the bore intersecting the boreI8. When the plug 24 is removed, a plurality of suitable projectiles 25may be inserted in the magazine 23, the projectiles being forced upwardin the magazine by means of a spring 26 interposed between the upper endof plug 24 and the lower surface of a washer 21 slidably mounted in thebore of the magazine. A firing chamber 28 is formed in the body at theright end of the barrel, and in order to prevent leakage `from thefiring chamber to atmosphere between the bore I8 and the surface of theplunger I9, a seal 29 is mounted in a groove 5 39 and is slidablyengaged by the outer surface of the plunger. When it is desired toinsert a projectile in the right end of the gun barrel, the 'i' handle2e is turned in a clockwise direction as, shown in Fig. 2, the plungeris withdrawn to the right sufficiently to permita projectile to enterthe bore l at the left of the plunger, and the plunger is then returnedto the position shown, a projection 3l formed on the left end of theplunger serving to move a projectile to the positien shown at 32. Thegun is now loaded, and it is only necessary to supply uid pressure inthe firing chamber in order to re the projectile from the gun.

A valve seat 33 is formed at the upper end of the iring chamber 28, anda valve 34 having a piston portion 34-a is slidably mounted in a bore 35forme-d in the body above and aligned with the ring chamber 28, thisvalve being norm mally maintained in closed position by means of aspring 36 interposed between the upper surface of the valve and a lowersurface of a plug 3l threadedly received by the body and serving toclose the upper end of the bore 35. An inlet chamber 38 formed in thelower end of the bore below the valve is connected with a firingreservoir 39 formed in the handle by means of a passage 40, and isconnected at its upper end to a portion of the bore above the valve bymeans of a passage 4l having a re- 35 stricted portion 42. The portionof the bore above the valve forms a control chamber 42-a which is alsoconnected with the cylinder i9 through a passage 43, a valve chamber 44,a passage 45 provided with a choke l5-a, a check valve chamber 46, and aport 4l, the latter port being normally closed by means of a check valve4S urged against the right end of the port by means of a spring 49mounted in the chamber 4G as Shown, the left end of the port 41 beingconnected with the cylinder l0. In view of the arrangement of the cupwasher l2 on the piston Il, it will be understood that fluid pressurewill be free to pass from the reservoir 1 to the reservoir 39 throughthe passage 9, by the piston cup i2 in the cylinder I0, port 41, checkvalve 43, valve chamber 45, passage 45, chamber 44, passage 43, bore 35,passage 4l, chamber 35, and passage 49, the result being that the smallring reservoir 39 is normally maintained at substan tially the samepressure as the supply reservoir '1, the only pressure difference beingthat due to the restriction imposed by the piston cup I2 and the checkvalve 48.

A trigger 50 is pivotally mounted on the body by means of a pivot pin l,the upper portion of the trigger at the right 'of the pivot pin 5l beingadapted to engage the lower end of a valve stem 52 slidably mounted in abore 53 formed in the body, an exhaust valve head 54 carried by theupper end of the stem being nor mally maintained in a position to closethe upper end of the bore by means of a spring 55 interposed between theupper end of the valve head and the lower surface of a plug 55 thread-70 edly received by the body. The stem of the valve is provided withnutes 51 which serve, when the valve is moved to open position, topermit the iiow of uid pressure from the valve chamber 44 to atmospherethrough an atmospheric port 53.

Thus on movement of the trigger in a counterclockwise direction aboutthe pivot pin, the valve 54 is moved to open position in order to allowiiuid pressure to exhaust from the valve chamber 44. When this actionoccurs, a sudden reduction of pressure occurs in the conduit 43 and inthe bore 35 above the valve 34, and the pressure in the chamber 38immediately forces the valve upward against the action of the spring 36to permit communication between the nring reservoir 39 and the iiringchamber 28 in order to discharge the projectile from the gun barrel. Atthe same time the piston 'portion 34-a of the valve closes the ends ofpassages 43 and 4|. As soon as the projectile leaves the gun barrel, thepressure drops rapidly in the chamber 38, and the valve is again movedto closed position by the action of the spring 33 as well as by theaction of the fluid pressure supplied from the reservoir 1 through thepassage previously described. Means are provided for automaticallyreturning the trigger to the position shown after the gun is red inorder to permit closing of valve 54, such means including a port 59connected at its lower end with the gun barrel and at its upper end withan enlarged bore 60 adapted to slidably receive a plunger 5|, the lowerend of the plunger thus being subjected to the pressure in the gunbarrel when the projectile passes to the left of the port 59, and theupper end of the plunger being in engagement with a portion of thetrigger at the left side of the pivot pin 5l. A suitable seal 62 isprovided for the purpose of preventing leakage past the plunger. Since arelatively high pressure is utilized for the operation of the gun, theforce exerted by the plunger is suicient to return the trigger to theposition shown regardless of the force exerted thereon by the operator,and when this occurs, the valve 54 is again returned to closed positionby the action of the spring 55. As soon as the valve 54 closes, thepressure again increases in the conduit 43, and the reservoir 39 isagain brought to the same pressure as the reservoir l. Thus the actionof the valve 34 is controlled by a sudden change in the pressuredifferential acting on the valveA which is produced by the operation ofthe valve 54, and no mechanical connection is required between thetrigger and the valve 34. Due to the rapid action of the gun, the amountof fluid pressure exhausted through the port 58 on operation of thetrigger is infinitesimal, and a very sensitive control of the ring valve34 is obtained.

With regard to the means utilized for charging the supply reservoir 1,it has been found that solid carbon dioxide or Dry Ice, when confined ina reservoir, reaches a state of equilibrium at a relatively highpressure, and that thereafter the carbon dioxide tends to change fromthe solid to the gaseous state to maintain the state of equilibriumwhenever gas is removed from the reservoir. It is therefore contemplatedthat in charging the gun, the plug 8 may be removedv and a suitableamount of solid carbon dioxide inserted in the reservoir 1 tosubstantially ll the space therein. The plug 8 is then replaced in orderto seal the lower end of the reservoir, and the gun is then charged withan adequate supply of gas sufiicient to insure repeated ring over aconsiderable period of time. v

During normal operation of the gun, sufficient pressure will bemaintained in the reservoir, duev to the change of the carbon dioxidefrom its solidied to its gaseous state, to insure'anadequatemuzzle'velocity of the projectile. In thel event it is desired to supplya higher pressure to the firing reservoir 39 in order to increase themuzzle velocity, the piston llmay be operatedto increase the pressure ofthe gas in the cylinder Ill, and to this end an operating handle 63 ispivotally mounted on they body of the gun by means of a suitable pivotpinrGd, a lever arm E35 above the pivot pin being adapted to engage thehead I6 of the piston rod I3. Thus during this type of operation, theoperator may operate the piston for any desired number of strokes tofurvther compress the gas in the cylinder. i0, and to deliver it to thereservoir 39 through the check valve 48 land the channels heretoforedescribed, it being understood that during thistype of operation theflexible sealing cup l2 on the piston acts as the inlet valve of thepump. :In this manner, gas at a higher pressure can be supplied to thereservoir 39 if desired with a relatively small amount of effort .on thepart of the operator, and muzzle velocities may be obtained if desiredwhich are far in excess of those obtainable in many of the guns of thisgeneral type heretofore in common use.

It is also contemplated that it may be desirF able to operate the gun inthe event of failure of the supply of gaseous carbon dioxide, and thismay be readily accomplished by removing the plug 8 from the lower end ofthe reservoir 1, whereupon the piston Il and the cylinder l will actsolely as a compressed air pump receiving air from atmosphere throughthe reservoir 'l and the passage 9 and compressing this air in thefiring reservoir 39, the pressure obtained inthe rng reservoir being inaccordance with the number of strokes given to the pump operating lever53,

As shown inthe, drawing. therbarrel of the sun isI preferably soarrangedas to lie between the nrst two iingers of the operators hand duringoperation of the gun, this resulting in anatural pointing Of the gurl bythe operator which is of material assistance in insuring extremeaccuracy in firing the gun. While the recoil of guns of this type isrelatively small, this positioning of the barrel is such in relation tovthe position of the hand of the operator as to substantially minimizethe effect of the recoil force on the aiming of the gun, another factorwhich contributes to extreme accuracy. i

There has thus been provided by the present invention a fluid pressureoperated gun of the repeater type adapted to be operated either by astored supply of compressed gas o r by compressed air1` and soconstituted as to be capable of carrying a charge of compressed gassufficient to insure repeated ring over a considerable yperiod of time,together With a construction which tends to insure extreme accuracy insuch firing. In the event of failure of the supply of stored gas underpressure, means have also been provided for permitting recharging of thegun with compressed air by the operation of a simple pump in theconventional manner, and means have also been provided for permittingthe operator to increase the pressure of fluid supplied to the ringchamber in excess of that obtaining in the supply reservoir. A triggercontrol mechanism for supplying fluid pressure to the firing chamber ofthe gun has also been provided which is relatively simple and extremelyefficient in operation, and which permits a trigger pull of any desiredvalue, the force required to operate the 6 'trigger being adjusted whenthe gun is designed llay-varying the leverage actingon the stern of `thetrigger-valve '54 and by varying the area of the valve itself. Simpleand emcient means have also been provided for `transferring projectilesfrom the magazine to the firing chamber of the gun, and for effectivelysealing the firing chamber against leakage while the gun is being fired.

'While the invention `has been illustrated and described herein withconsiderable particularity, it is to be clearly understood that the sameis not limited tothe forms shown, but may receive a variety ofmechanical expressions, as Will readily appear to those skilled in theart. Refer- Aence will, therefore, be had to the appended 'claims for adefinition of the limits of the invention.

This application is a division of the application of Ellery R. Fitch,kSerial Number 570,189, 'newA Patent No. 2,566,181, led December 28,ltlii, for Fluid Pressure vOperated Gun.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

l. In a fluid pressure operated gun having a casing provided with abarrel adapted to receive a projectile at one end thereof, a reservoirfor compressed fluid in the casing, a firing chamber adjacent said oneend of said barrel and communicating therewith, means including anoperator-controlled valve for supplying a charge of compressed fluid`from the reservoir to the ring chamber to re the projectile, and meansfor supplying projectiles to the barrel including a magazine in thecasing adapted to be charged with a plurality of projectiles, a bore inthe casing having connection with the magazine and connected at one endwith the ring chamber and barrel, means for biasing the projectiles inthe magazine. toward said bore, and means for transferring projectilesfrom the magazine to the barrel and for normally preventing leakage offluid from the ring chamber through said bore including a solid plungerslidably mounted in said bore. slidable in one direction to open theconnection between the bore and magazine to permit the transfer of aprojectile from the maga- Zine to the bore by the action of the biasingmeans and slidable in the opposite direction to close the connectionbetween the bore and magazine and engage and to move the projectile tosaid one end, of said barrel adjacent the firing chamber, and sealingmeans carried by the casing around said bore and engageable by saidplunger on sliding movement in said opposite direction for preventingleakage of fluid pressure from the firing chamber through the bore. 2*.In a fluid pressure operated gun having a casing provided with a barreladapted to receive a projectile at one end thereof, a reservoir forcompressed fluid in the casing, a ring chamber adjacent said one end ofsaid barrel and communicating therewith, means including anoperator-controlled valve for supplying a charge of compressed uid fromthe reservoir to the firing chamber to re the projectile, and means forsupplying projectiles to the barrel including a magazine in the casingadapted to be charged with a plurality of projectiles, a bore in thecasing having connection with the magazine and connected at one end withthe firing chamber and barrel, means for biasing the projectiles in themagazine toward said bore, means for transferring projectiles from themagazine to the barrel and for normally preventing leakage of fluid fromthe firing chamber through said bore including a solid plunger slidablymounted in said bore slidable in one direction to open the connectionbetween the bore and magazine to permit the transfer of a projectilefrom the magazine to the bore under the action of the biasing means andslidable in the opposite direction to close the connection between thebore and magazine and engage and to move said projectile to said one endof said barrel adjacent said firing chamber, sealing means carried bythe casing around the bore and engageable by said plunger on slidingmovement in said opposite direction for preventing leakage of uidpressure from the firing chamber through the bore, and means for lockingthe plunger when moved in said opposite direction.

3. In a uid pressure operated gun having a body provided with a barrelfor receiving a projectile adjacent one end thereof, a reservoir ofcompressed uid carried by the body, a firing chamber communicating withsaid barrel, means including a Valve for connecting said reservoir andiiring chamber to charge the latter with compressed fluid to re theprojectile, and means for supplying projectiles to the barrel comprisinga magazine containing a plurality of projectiles, said magazinecommunicating with the barrel and the firing chamber, a spring in themagazine for constantly urging said projectiles toward the barrel, asolid plunger slidable in said body to one position to opencommunication between the barrel and the magazine and to anotherposition to close communication between the barrel and the magazine, andsealing means associated with said plunger and body for preventingleakage of fluid pressure from the firing chamber past said plunger.

4. In a uid pressure operated gun having a body provided with a barrelfor receiving a projectile adjacent one end thereof, a reservoir ofcompressed fluid carried by the body, a iiring chamber communicatingwith said barrel, means including a valve for connecting said reservoirand firing chamber to charge the latter with compressed fluid to firethe projectile, and means for supplying projectiles to the barrelcomprising a magazine containing a plurality of projectiles, saidmagazine communicating with the barrel and the firing chamber, a springin the magazine for constantly urging said projectiles toward thebarrel, said body having a bore connecting said firing chamber andmagazine and connected with the atmosphere, a solid plunger positionedin said bore to close the atmospheric connection and slidable in saidbore in one direction to open communication between the barrel and themagazine to allow a projectile to move into the bore under the action ofsaid spring, and slidable in the other direction to close communicationbetween the firing chamber and the magazine, said plunger having one endengaged with said projectile when moved in said other direction to movethe projectile into said barrel in advance of said firing chamber, andsealing means carried by the body around said bore and engaged by saidplunger for preventing leakage of fluid pressure from the firing chamberthrough the bore when the plunger is moved in said other direction.

5. In a uid pressure operated gun having a body provided with a barreladapted to receive a projectile at one end thereof, a reservoir forcompressed fluid carried by the body, a ring chamber adjacent said oneend of said barrel, means including an operator-controlled valve forsupplying a charge of compressed fluid from the reservoir to the ringchamber to re the projectile, and means for supplying projectiles to thebarrel including a magazine in the body adapted to be charged with aplurality of projectiles, a bore in the body having a connection Withthe magazine and connected at one end with the firing chamber, said borebeing aligned with said barrel and having a connection with theatmosphere, means for biasing the projectiles -in the magazine towardsaid bore, means for transferring projectiles from the magazine to thebarrel and for normally preventing leakage of fluid from the firingchamber through the bore including a solid plunger positioned in saidbore to close the atmospheric connection and being slidable in said borein one direction to open the connection with the bore and magazine topermit the transfer of a projectile from the magazine to the bore underthe action of biasing means and slidable in the other direction to closethe connection between the bore and magazine said plunger having one endengaged with said projectile when moved in said other direction to movesaid projectile to said one end of said barrel through said ringchamber, sealing means carried by said body around said bore andengageable by said plunger on movement in said other direction forpreventing leakage of fluid pressure from the firing chamber through thebore, and means for locking the plunger when moved in said otherdirection.

ELLERY R. FITCH.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,512,993 McLean Oct. 28, 1924 1,862,697 Mihalyi June 14, 19322,495,829 Vincent Jan. 31, 1950 2,528,462 Wells Oct. 31, 1950

